Technical Field
The present disclosure relates to a display scan device, particularly to a display scan device with a touch function.
Description of the Related Art
Recently, various liquid crystal display products are widely applied to mobile handheld devices, and because smart terminal devices are generally applied to various fields, integrating touch function to the smart terminal devices is the main stream of the current products.
Please refer to FIG. 1. FIG. 1 is a waveform diagram of the shift register in the prior art. As shown in FIG. 1, the touch display apparatus with the touch display function in the prior art activates the touch driver to perform touch driving in the stop-displaying interval. The display driver includes a plurality of shift register circuits, clocks CK1, CK2, scan signals G(n−1), G(n), and driving voltages Q(n−1), Q(n). In every frame, the shift register circuit outputs the scan signal to the display panel according to the clock. For example, the shift register circuit pulls up the driving voltage Q(n−1) of the internal node to output the scan signal G(n−1) according to the clock CK1. In the stop-displaying interval, the shift register stops outputting the display driving signal G(n), and the clock CK and the control signal LC are disabled, so that the driving voltage Q(n) of the node Q is floating and the driving voltage Q(n) of the node Q leaks with time. When the disabled time of the clock CK, the control signal LC, and other external signals are longer, the electric leakage problem of the driving voltage Q(n) is getting serious. When the display driving is resumed, the scan signal G(n−1) outputted from the enabled clock CK2 leaks due to the floating of the internal node in the display driving circuit during the stop-displaying interval, and the problem further results in the incapability of outputting correct voltage level from the scan signal G(n) after the stop-displaying interval. Therefore, the display quality is decreased.
Therefore, how to maintain the display driver not to leak and to output incorrectly during the touch driving period or the stop-displaying interval is a development issue, and the problem becomes a target for improvement in the related fields.